Manufacture of seamless tubing.



PATENTED JAN. 14, 1908.

G. H. BLAXTER.

MANUFACTURE OF SBAMLESS TUBING.

APPLICATION FILED JUNE 25,1906.

WifiuwSes: 65, 0%. mow v 4 UNITED STATES" PATENT OFFICE."

GEORGE H. BLAXIER, OF NEW BRIGHTON, PENNSYLVANIA.

MANUFACTURE OF SEAMLESS TUBING.

Specification of Letters Patent.

Patented Jan. 14, 1998 Application filed nne 25. 1906- Serial No. 323J89i To all whom it may concern: Be it known that I, GEORGE H. BLAXTER, a citizen of Great Britain, residing at New Brighton, in the county of'Beavcr and State and consists in the process or method of formmg an already prepared tubular blank upon a mandrel provided with a terminal ball, over which the tube is forced by means of grooved reducing rolls. Also in subsequently rolling the formed tube while upon the mandrel between grooved rolls so arranged as to further compress the walls of the tube which is finallyremoved from the mandrel in finished sha )e.

The principa object of the. invention is to obtain a. perfectly finished smooth tube, both inside and outside.

The process involves the preliminary manipulation of the tubular blankto introduce it to the first set of rolls and over the terminal ball of the mandrel; means by which the mandrel and tube. are transferred from the first set of compressing rolls to the finishing rolls; means for centralizing and guiding the mandrel and tube-in-process; with the necessary moving or carrying elements or devices for finally removing the finished tube and inandrel, as will be readily understood.

The invention has in view the forming of a smooth finished interior surface by first passing the blank over the mandrelball to reduce the thickness of the walls and to completely remove. all scale or other adhering matter, and then finishing the tube on the mandrel bar under pressing rolls.

Referring now to the drawings wherein the invention is illustrated; Figure 1 represents a vertical longitudinal sectional view of continuous-roll mechanism for carrying out my improved process, showing the introduction of the tubular blank to the compressing rolls. Fig. 2. is a. similar view showing the tube surrounding the mandrel after passing through and beyond said rolls, and in'progress toward the finishing rolls. Fig. 3. is a similar View showing the tube and mandrel passing through the finishing rolls. Fi s. 4 and 5 are detail sectional views on the lines IV. IV. and V. V. of Fig. 3 illustrating graphically.the operation ofthe finishing rolls upon the tube.

. 2 represents the tubular blank a it domes from the piercim mill or other mm hanism, '0

being introduced between grooved rolls 3, 3, and over the ball 4 of mandrel 5, the blank being forced between the rolls by anysuitable means, as a pusher 6.

The-mandrel 5 and its ball 4 are supported 5 and maintained in alinement 1n any suitable manner, by under grooved rollers 7 and oneor more upper rollers 8, which hold llcentrally in almeluent and in proper positlon with relation to the grooves or rolls 3. The 7 back end of mandrel 5 abuts against a gate or stop 9 which receives the force of impact of the mandrel during the process of forcing the blank 2 overthe ball between the rolls,

after which operation the ball ordinarily falls away from the mandrel. Duri such 0 v ation over the ball the-blank is cleared oit ll scale inside and out, the blank then being. com ressedand elongated, while carried on" the ody shown in ig. 2, the,-walls of the tube beingredulced to nearly the finished thickness do siret Beyond the rolls 3 and arranged in suitable relation to the mandrel 5 and its surrounding 35 tube 10, are pairs of grooved rolls '11, 12, preferalaly located alternately in horizontal and vertical planes" as shown, whereby the first pair of rolls will engage the tube 10 at opposite sides, the'next succeedin air en a n s P g g g it at intervening positions, at t e same time. It will bennderstood that any number of pairs of rolls may be employed or that their position with relation to each other may be varied within the judgment of the o erator 9'5 or depending upon the, work in ham The operation and effect of such grooved rolls 11, 1?, isto further compress .tlie'walls of the tube 10 u on mandrel 5, iving the required uniform t ickness throng out, and effecting a smooth olished surface both inside an out. The rther result of thjbperation o said rolls is that theinternal diameter of the tube 10 is s lig-htly increased and the tube is freed from adherence to themandrel 5, by

reason of the' fact that the compressing faces of the rolls operating at opposite sides, tend to'eause the tube to bulge out, at the intervening portions as indicated at 13 Fi s. 4 and 5, thus greatly facilitating the wor' of re- 11c rtion o'f the'mandrel, as clearly so '10 anjt adlie'ring scale or dirt, and thus allows the finishing passes to be made on the clean metal of the mandrel inn, contacting with the clean interior of the-blank. 2

Changes or'yariat-ions Iniiy be mnd in the '15 mechanism-by which th operation, 15 ers f or in thesteps of the proc s,-hut a l l r. such changes are to be considered as within the smpc of the following claims.

\\ lmt'l (-laim is:

In tho manufacture of seamless tubing, the Z0- procosslol' forcmgu h'vntvd tuhularfblank hvtween rvducing moans over and onto a-mandrel lmr, and then reducing the tuhv-surrounding llll mandrel bar between said bar and outside reducing means,

In testimony whereof I aflik my signature in prosvncooi two witnesses.

GEORGE u. BLAXTERQ Witn'essesi Cims. LEPLEY, 0, M. CLARKE; 

